过滤在线编辑器产生的不安全html代码.

<?php
/**
*过滤在线编辑器产生的不安全html代码.
*
*PHPversions4and5
*
*@copyright版权所无，任意传播.
*@linkhttp://www.52sunny.net
*@namehtml过滤
*@versionv0.0.10
*@authorLucklrj(sunny_lrj@yeah.net,qq:7691272)
*@lastmodified2006-06-0910:42(Tue,2006-06-09)
*@notice此版本只过滤js,框架，表单。
作者能力有限，使用本程序若产生任何安全问题，与本人无关。
欢迎来信与我交流。
*/
$str="<tr><tdbgcolor='#FFFFFF'>
<divstyle='url(123.offsetWidth)>";
//$str="url(javascript:x)";

/*不需要过滤的数组*/
$htm_on=array(
"<acronym","acronym>",
"<baseFont","baseFont>",
"<button","button>",
"<caption","caption>",
"<clientInformation","clientInformation>",
"<font","font>",
"<implementation","implementation>",
"<button","button>",
"<location","location>",
"<option","option>",
"<selection","selection>",
"<strong","strong>");

$htm_on_uper=array(
"<ACRONYM","ACRONYM>",
"<BASEFONT","BASEFONT>",
"<BUTTON","BUTTON>",
"<CAPTION","CAPTION>",
"<CLIENTINFORMATION","CLIENTINFORMATION>",
"<FONT","FONT>",
"<IMPLEMENTATION","IMPLEMENTATION>",
"<BUTTON","BUTTON>",
"<LOCATION","LOCATION>",
"<OPTION","OPTION>",
"<SELECTION","SELECTION>",
"<STRONG","STRONG>");

/*字符格式*/
$str=strtolower($str);
$str=preg_replace("/s+/","",$str);//过滤回车
$str=preg_replace("/+/","",$str);//过滤多个空格

/*过滤/替换几种形式的js*/
$str=preg_replace("/<(script.*?)>(.*?)<(/script.*?)>/si","",$str);//删除<script>。。。</script>格式，
//$str=preg_replace("/<(script.*?)>(.*?)<(/script.*?)>/si","&lt;/1&gt;/2&lt;/3&gt;",$str);//替换为可以显示的，

$str=preg_replace("/<(script.*?)>/si","",$str);//删除<script>未封闭
//$str=preg_replace("/<(script.*?)>/si","&lt;/1&gt;",$str);//替换未封闭

/*删除/替换表单*/
$str=preg_replace("/<(/?form.*?)>/si","",$str);//删除表单
//$str=preg_replace("/<(/?form.*?)>/si","&lt;/1&gt;",$str);//替换表单

$str=preg_replace("/<(i?frame.*?)>(.*?)<(/i?frame.*?)>/si","",$str);//删除框架
//$str=preg_replace("/<(i?frame.*?)>(.*?)<(/i?frame.*?)>/si","&lt;/1&gt;/2&lt;/3&gt;",$str);//替换框架

/*过滤on事件*/
$str=preg_replace("/href=(.+?)(["|'||>])/ie","'href='.strtoupper('/1').'/2'",$str);//把href=涉及到的on转换为大写。
$str=str_replace($htm_on,$htm_on_uper,$str);//把<font,font>换为大写,dhtml标签字符，正则判断太烦琐，采用转换办法。
$str=preg_replace("/(on[^.<>]+?)([|>])/s","/2",$str);//取掉on事件

/*过滤超级连接的js*/
$str=preg_replace("/(href|src|background|url|dynsrc|expression|codebase)[=:(](["']*?w+..*?|javascript|vbscript:[^>]*?)()?)([>/])/si","/1='#'/3/4",$str);//取掉href=javascript:

//返回小写字符
$str=strtolower($str);
$str=str_replace("&","&#x26;",$str);
echo$str;
?>